(a) Field of the Invention
The present invention relates to a catheter having an X-ray contrast medium function.
(b) Description of the Prior Art
Various types of catheters such as an angiographic catheter, a cardiac minute volume measuring catheter, a ureteral catheter, a cholangiographic catheter, bronchographic tube, and a thoracic catheter have been conventionally used for indwelling in body cavities. An X-ray contrast medium is mixed partially or entirely in these catheters, or employed to circumferentially form a ring mark on the outer surface of the catheters. A doctor inserts a catheter having an X-ray contrast medium function into a body cavity while observing an X-ray fluoroscopic image.
The X-ray fluoroscopic image is a two-dimensional type image, so that even if the curved distal end portion of the catheter is twisted in a rotational direction with respect to the proximal axis, or if the catheter itself is deviated toward the rotational direction, the resultant X-ray fluoroscopic image is substantially the same as that obtained along the intended, i.e., the correct direction. The doctor may mistakenly believe that the catheter is directed correctly toward the fluoroscopic plane.
For this reason, when a Judkins type angiographic catheter is inserted in the right coronary artery, with the distal end portion 1a thereof being deviated from right coronary artery port A, as shown in FIG. 1a, the doctor observes the X-ray fluoroscopic image shown in FIG. 1b, and mistakenly believes that he can insert distal end portion 1a into port A. For this reason, insertion operations often have to be repeated, since the catheter sometimes cannot easily be inserted into the location of interest. As a result, the time taken to perform the insertion operation is prolonged and the insertion process causes pain and discomfort to the patient.